Biphenyl, C12H10, is a nonvolatile, nonionizing solute that is soluble in benzene, C6H6. At 25 °C, the vapor pressure of pure benzene is 100.84 torr. What is the vapor pressure of a solution made from dissolving 12.5 g of biphenyl in 27.9 g of benzene?

Answer 1

mole fraction benzene = XC6H6 = moles benzene/total mols.
mols benzene = grams/molar mass
mols biphenyl = grams/molar mass

Then p_C6H6 = X_C6H6 * P^o_C6H6 = ?